LEMON Manuals: Even more car manuals for everyone
Home >> Mazda >> 2007 >> B4000 SE, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 70 (Engine Controls - Self-Diagnostics) >> Diagnostic Tests >> DTC P0603, DTC P1605, DTC P1633 Or DTC P1639 >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2003 Mazda B4000, 2003 Mazda B3000, and 2003 Mazda B2300. However, it is still accessible from the selected car via links, so may be relevant.
  1. If QUICK TEST was not performed, go to QUICK TEST  under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed, go to next step.
    2. NOTE: If PCM KAPWR is interrupted (i.e. when installing or removing breakout box or battery disconnect), DTCs P0603 and/or P1605 may be set on first power-up.
  2. Check Battery Terminals -  Inspect battery cables for loose connections and corrosion. If battery cable connections are okay, go to next step. If battery cable connections are not okay, repair as necessary. After repair, go to step  5 .
  3. Inspect Engine Compartment For Proper Wire Routing -  Inspect engine compartment for proper wire routing paying specific attention to ignition components and wires. If wiring is to close to ignition components or wires, reroute wires as necessary. After repair, go to step  5 . If wiring is not to close to ignition components or wires, wire routing is okay. Go to next step.
  4. Check Keep Alive Power (KAPWR) To PCM -  Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. See Figure . Measure voltage between breakout box terminals No. 55 (KAPWR circuit) and No. 103 (PWR GND circuit). While observing DVOM, wiggle and shake wiring harness, and bend wiring harness working from PCM to dash panel. If voltage reading is less than 10.5 volts at any time, isolate and repair open in KAPWR circuit (Yellow wire) between PCM 104-pin harness connector terminal No. 55 and No. 21 PCM fuse (10-amp) in under-hood fuse/relay box. After repair, go to next step. If voltage reading did not drop to less than 10.5 volts, KAPWR circuit is okay. Go to next step.
  5. Verify Trouble Shooting Of DTCs Completed -  Reconnect all electrical connectors. Clear DTCs from PCM memory using scan tool. Perform QUICK TEST  under SELF-DIAGNOSTIC SYSTEM. If same DTC is present, replace faulty PCM. Repeat QUICK TEST  under SELF-DIAGNOSTIC SYSTEM. If any other DTC is present, go to applicable procedure for other DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS  . If no DTC is present, trouble shooting is complete.
scientia non olet · About LEMON Manuals